Steller's eider (Polysticta stelleri) is a migrating Arctic diving duck that breeds along the coastlines of eastern Russia and Alaska.

[3] Due to the extensive contraction of its breeding range, the Alaska-breeding population of Steller's eider was listed as vulnerable in 1997 by the International Union for the Conservation of Nature (IUCN).

[4][5] Steller's eider was formally described and illustrated in 1769 by the German naturalist Peter Simon Pallas from a specimen collected on the Kamchatka Peninsula in Eastern Russia.

He coined the binomial name Anas stelleri; the specific epithet was chosen to honour the German naturalist and explorer Georg Wilhelm Steller.

[15] In mid-summer to fall, males assume their non-breeding plumage which is primarily dark brown with a white-bordered bluish speculum (secondary feathers) on their wing.

During the winter, Steller’s eiders occupy coastal bays and lagoons that offer suitable forage while occasionally feeding in deeper waters that remain adequately sheltered.

[14] Within the marshy tundra, they designate specific areas to build their nest, preferring elevated surfaces covered by shallow vegetation such as mosses and grasses.

[14] Their molting habitat consists of relatively shallow coastal lagoons that offer viable eelgrass and tidal flats for foraging and beaches and sandbars to rest while they remain flightless.

Some non-breeding populations will also spend their summers in northern Norway, on the east coast of Russia and adjacent waters, and south-west Alaska.

[18] Steller's eiders forage primarily near the shore by employing various techniques such as briefly diving and swimming underwater (to a maximum depth of 9m), wading and dabbling.

[21] Studies have shown that Steller's eiders are specialists in catching highly mobile prey but may limit their diet to crustaceans even when higher energy sources, such as capelin, become available.

[25] Females establish their nests in marshy tundra close to permanent open water that has additional access to small ponds.

[14] After breeding, Steller's eiders gather in high-density flocks to synchronously molt (replace all their feather at the same time) in Arctic lagoons in northwest Asia and along the Alaska peninsula.

It has been attributed to changes to the Arctic climate, increased predation rates, hunting and consumption of lead shot, and disease.

Primarily, climate change has caused Arctic tundra ponds to disappear, limiting the extent of suitable habitat for the species.

[29] Climate change has also been implicated in the collapse of rodent populations, forcing predators to exploit alternative prey such as the eggs and young of Steller's eider.

[34] E. coli has also been reported in Alaska-breeding Steller’s eiders and is thought to be linked to wastewater from local human communities and industrialization.

Fish and Wildlife Service predicts that if the plan is adequately funded and properly implemented, the recovery criteria could be met by 2050.

[37] In 2016, the global population of Steller’s eider was estimated at 110,000-125,000 individuals and classified as vulnerable by the International Union for the Conservation of Nature (IUCN).